The Orioles called up right-hander Bob McCrory from Triple-A Norfolk to take Sarfate's place on the roster, and he was expected to arrive in Toronto late Sunday morning.
Sarfate saw a cardiovascular surgeon on Saturday in Toronto after he left Friday's 8-4 loss to the Blue Jays during the seventh inning because he lost feeling in the middle finger of his pitching hand, something he previously had never experienced.
"I've got a little bit of blockage in my upper bicep, shoulder area," Sarfate said Sunday at Rogers Centre. "It's pinching off one of the blood vessels, or whatever it is. Hopefully, they said, it's a muscle mass that is blocking it so we can avoid any kind of surgery."
Sarfate went on the disabled list last September with a right distal clavicle fracture that required surgery.
"The surgeon here was very sure that it wasn't related to any kind of surgery I've had," Sarfate said. "It wasn't even close to that area. ... The important thing it's not something serious. It's not life-threatening. It could be career threatening. Who knows? Hopefully this blockage can get fixed, and we'll go from there. If it's 15 days, awesome. If it's more than that, as long as I come back healthy, I don't care."
When Sarfate was asked about whether it could be career threatening, he said nothing more will be known about the extent of the problem until Monday's procedure.
"Until we get the angiogram and see what's going on more closely in there, we don't even know," Sarfate said. "I'm glad it's not something serious, nothing to do with the heart or anything like that. They said it's common in athletes, where they usually get some blockage up there from muscle mass and all that. I feel confident with what the surgeon told me yesterday, and hopefully we can go on and get it fixed."
Sarfate was 4-3 with a 4.74 ERA in 57 games, including four starts, for the Orioles last season. This season his velocity was down noticeably, but he said Friday that he was confident that it would return as the season progressed. Sarfate attributed it to coming back from surgery. In eight games this season, he has a 6.39 ERA and no decisions.
"Everybody loves Dennis and knows how Dennis is," Baltimore manager Dave Trembley said, "and Dennis is worried. And we tried to reassure him that he is going to be properly taken care of and we'll get him back OK. Right now I couldn't tell you how long it's going to be."
Larry Millson is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.